1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2007, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, USA. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
27 with Csets; use Csets;
28 with Stylesw; use Stylesw;
29 with Uintp; use Uintp;
31 with GNAT.Spelling_Checker; use GNAT.Spelling_Checker;
40 function Bad_Spelling_Of (T : Token_Type) return Boolean is
41 Tname : constant String := Token_Type'Image (T);
42 -- Characters of token name
44 S : String (1 .. Tname'Last - 4);
45 -- Characters of token name folded to lower case, omitting TOK_ at start
47 M1 : String (1 .. 42) := "incorrect spelling of keyword ************";
48 M2 : String (1 .. 44) := "illegal abbreviation of keyword ************";
49 -- Buffers used to construct error message
53 -- Starting subscripts in M1, M2 for keyword name
55 SL : constant Natural := S'Length;
56 -- Length of expected token name excluding TOK_ at start
59 if Token /= Tok_Identifier then
64 S (J) := Fold_Lower (Tname (Integer (J) + 4));
67 Get_Name_String (Token_Name);
69 -- A special check for case of PROGRAM used for PROCEDURE
73 and then Name_Buffer (1 .. 7) = "program"
75 Error_Msg_SC ("PROCEDURE expected");
79 -- A special check for an illegal abbrevation
81 elsif Name_Len < S'Length
82 and then Name_Len >= 4
83 and then Name_Buffer (1 .. Name_Len) = S (1 .. Name_Len)
85 for J in 1 .. S'Last loop
86 M2 (P2 + J - 1) := Fold_Upper (S (J));
89 Error_Msg_SC (M2 (1 .. P2 - 1 + S'Last));
94 -- Now we go into the full circuit to check for a misspelling
96 -- Never consider something a misspelling if either the actual or
97 -- expected string is less than 3 characters (before this check we
98 -- used to consider i to be a misspelled if in some cases!)
100 if SL < 3 or else Name_Len < 3 then
103 -- Special case: prefix matches, i.e. the leading characters of the
104 -- token that we have exactly match the required keyword. If there
105 -- are at least two characters left over, assume that we have a case
106 -- of two keywords joined together which should not be joined.
108 elsif Name_Len > SL + 1
109 and then S = Name_Buffer (1 .. SL)
111 Scan_Ptr := Token_Ptr + S'Length;
112 Error_Msg_S ("missing space");
117 if Is_Bad_Spelling_Of (Name_Buffer (1 .. Name_Len), S) then
118 for J in 1 .. S'Last loop
119 M1 (P1 + J - 1) := Fold_Upper (S (J));
122 Error_Msg_SC (M1 (1 .. P1 - 1 + S'Last));
131 ----------------------
132 -- Check_95_Keyword --
133 ----------------------
135 -- On entry, the caller has checked that current token is an identifier
136 -- whose name matches the name of the 95 keyword New_Tok.
138 procedure Check_95_Keyword (Token_95, Next : Token_Type) is
139 Scan_State : Saved_Scan_State;
142 Save_Scan_State (Scan_State); -- at identifier/keyword
143 Scan; -- past identifier/keyword
146 Restore_Scan_State (Scan_State); -- to identifier
147 Error_Msg_Name_1 := Token_Name;
148 Error_Msg_SC ("(Ada 83) keyword* cannot be used!");
151 Restore_Scan_State (Scan_State); -- to identifier
153 end Check_95_Keyword;
155 ----------------------
156 -- Check_Bad_Layout --
157 ----------------------
159 procedure Check_Bad_Layout is
161 if Style.RM_Column_Check and then Token_Is_At_Start_Of_Line
162 and then Start_Column <= Scope.Table (Scope.Last).Ecol
164 Error_Msg_BC ("(style) incorrect layout");
166 end Check_Bad_Layout;
168 --------------------------
169 -- Check_Misspelling_Of --
170 --------------------------
172 procedure Check_Misspelling_Of (T : Token_Type) is
174 if Bad_Spelling_Of (T) then
177 end Check_Misspelling_Of;
179 --------------------------
180 -- Check_No_Right_Paren --
181 --------------------------
183 procedure Check_No_Right_Paren is
185 if Token = Tok_Right_Paren then
186 Error_Msg_SC ("unexpected right parenthesis");
187 Scan; -- past unexpected right paren
189 end Check_No_Right_Paren;
191 -----------------------------
192 -- Check_Simple_Expression --
193 -----------------------------
195 procedure Check_Simple_Expression (E : Node_Id) is
197 if Expr_Form = EF_Non_Simple then
198 Error_Msg_N ("this expression must be parenthesized", E);
200 end Check_Simple_Expression;
202 ---------------------------------------
203 -- Check_Simple_Expression_In_Ada_83 --
204 ---------------------------------------
206 procedure Check_Simple_Expression_In_Ada_83 (E : Node_Id) is
208 if Expr_Form = EF_Non_Simple then
209 if Ada_Version = Ada_83 then
210 Error_Msg_N ("(Ada 83) this expression must be parenthesized!", E);
213 end Check_Simple_Expression_In_Ada_83;
215 ------------------------
216 -- Check_Subtype_Mark --
217 ------------------------
219 function Check_Subtype_Mark (Mark : Node_Id) return Node_Id is
221 if Nkind (Mark) = N_Identifier
222 or else Nkind (Mark) = N_Selected_Component
223 or else (Nkind (Mark) = N_Attribute_Reference
224 and then Is_Type_Attribute_Name (Attribute_Name (Mark)))
229 Error_Msg ("subtype mark expected", Sloc (Mark));
232 end Check_Subtype_Mark;
238 function Comma_Present return Boolean is
239 Scan_State : Saved_Scan_State;
243 -- First check, if a comma is present, then a comma is present!
245 if Token = Tok_Comma then
249 -- If we have a right paren, then that is taken as ending the list
250 -- i.e. no comma is present.
252 elsif Token = Tok_Right_Paren then
255 -- If pragmas, then get rid of them and make a recursive call
256 -- to process what follows these pragmas.
258 elsif Token = Tok_Pragma then
260 return Comma_Present;
262 -- At this stage we have an error, and the goal is to decide on whether
263 -- or not we should diagnose an error and report a (non-existent)
264 -- comma as being present, or simply to report no comma is present
266 -- If we are a semicolon, then the question is whether we have a missing
267 -- right paren, or whether the semicolon should have been a comma. To
268 -- guess the right answer, we scan ahead keeping track of the paren
269 -- level, looking for a clue that helps us make the right decision.
271 -- This approach is highly accurate in the single error case, and does
272 -- not make bad mistakes in the multiple error case (indeed we can't
273 -- really make a very bad decision at this point in any case).
275 elsif Token = Tok_Semicolon then
276 Save_Scan_State (Scan_State);
277 Scan; -- past semicolon
279 -- Check for being followed by identifier => which almost certainly
280 -- means we are still in a parameter list and the comma should have
281 -- been a semicolon (such a sequence could not follow a semicolon)
283 if Token = Tok_Identifier then
286 if Token = Tok_Arrow then
291 -- If that test didn't work, loop ahead looking for a comma or
292 -- semicolon at the same parenthesis level. Always remember that
293 -- we can't go badly wrong in an error situation like this!
297 -- Here is the look ahead loop, Paren_Count tells us whether the
298 -- token we are looking at is at the same paren level as the
299 -- suspicious semicolon that we are trying to figure out.
303 -- If we hit another semicolon or an end of file, and we have
304 -- not seen a right paren or another comma on the way, then
305 -- probably the semicolon did end the list. Indeed that is
306 -- certainly the only single error correction possible here.
308 if Token = Tok_Semicolon or else Token = Tok_EOF then
309 Restore_Scan_State (Scan_State);
312 -- A comma at the same paren level as the semicolon is a strong
313 -- indicator that the semicolon should have been a comma, indeed
314 -- again this is the only possible single error correction.
316 elsif Token = Tok_Comma then
317 exit when Paren_Count = 0;
319 -- A left paren just bumps the paren count
321 elsif Token = Tok_Left_Paren then
322 Paren_Count := Paren_Count + 1;
324 -- A right paren that is at the same paren level as the semicolon
325 -- also means that the only possible single error correction is
326 -- to assume that the semicolon should have been a comma. If we
327 -- are not at the same paren level, then adjust the paren level.
329 elsif Token = Tok_Right_Paren then
330 exit when Paren_Count = 0;
331 Paren_Count := Paren_Count - 1;
334 -- Keep going, we haven't made a decision yet
339 -- If we fall through the loop, it means that we found a terminating
340 -- right paren or another comma. In either case it is reasonable to
341 -- assume that the semicolon was really intended to be a comma. Also
342 -- come here for the identifier arrow case.
345 Restore_Scan_State (Scan_State);
346 Error_Msg_SC (""";"" illegal here, replaced by "",""");
347 Scan; -- past the semicolon
350 -- If we are not at semicolon or a right paren, then we base the
351 -- decision on whether or not the next token can be part of an
352 -- expression. If not, then decide that no comma is present (the
353 -- caller will eventually generate a missing right parent message)
355 elsif Token in Token_Class_Eterm then
358 -- Otherwise we assume a comma is present, even if none is present,
359 -- since the next token must be part of an expression, so if we were
360 -- at the end of the list, then there is more than one error present.
363 T_Comma; -- to give error
368 -----------------------
369 -- Discard_Junk_List --
370 -----------------------
372 procedure Discard_Junk_List (L : List_Id) is
373 pragma Warnings (Off, L);
376 end Discard_Junk_List;
378 -----------------------
379 -- Discard_Junk_Node --
380 -----------------------
382 procedure Discard_Junk_Node (N : Node_Id) is
383 pragma Warnings (Off, N);
386 end Discard_Junk_Node;
392 procedure Ignore (T : Token_Type) is
395 if T = Tok_Comma then
396 Error_Msg_SC ("unexpected "","" ignored");
398 elsif T = Tok_Left_Paren then
399 Error_Msg_SC ("unexpected ""("" ignored");
401 elsif T = Tok_Right_Paren then
402 Error_Msg_SC ("unexpected "")"" ignored");
404 elsif T = Tok_Semicolon then
405 Error_Msg_SC ("unexpected "";"" ignored");
409 Tname : constant String := Token_Type'Image (Token);
410 Msg : String := "unexpected keyword ????????????????????????";
413 -- Loop to copy characters of keyword name (ignoring Tok_)
415 for J in 5 .. Tname'Last loop
416 Msg (J + 14) := Fold_Upper (Tname (J));
419 Msg (Tname'Last + 15 .. Tname'Last + 22) := " ignored";
420 Error_Msg_SC (Msg (1 .. Tname'Last + 22));
424 Scan; -- Scan past ignored token
428 ----------------------------
429 -- Is_Reserved_Identifier --
430 ----------------------------
432 function Is_Reserved_Identifier (C : Id_Check := None) return Boolean is
434 if not Is_Reserved_Keyword (Token) then
439 Ident_Casing : constant Casing_Type :=
440 Identifier_Casing (Current_Source_File);
442 Key_Casing : constant Casing_Type :=
443 Keyword_Casing (Current_Source_File);
446 -- If the casing of identifiers and keywords is different in
447 -- this source file, and the casing of this token matches the
448 -- keyword casing, then we return False, since it is pretty
449 -- clearly intended to be a keyword.
451 if Ident_Casing = Unknown
452 or else Key_Casing = Unknown
453 or else Ident_Casing = Key_Casing
454 or else Determine_Token_Casing /= Key_Casing
458 -- Here we have a keyword written clearly with keyword casing.
459 -- In default mode, we would not be willing to consider this as
460 -- a reserved identifier, but if C is set, we may still accept it
464 Scan_State : Saved_Scan_State;
465 OK_Next_Tok : Boolean;
468 Save_Scan_State (Scan_State);
471 if Token_Is_At_Start_Of_Line then
479 when C_Comma_Right_Paren =>
481 Token = Tok_Comma or else Token = Tok_Right_Paren;
483 when C_Comma_Colon =>
485 Token = Tok_Comma or else Token = Tok_Colon;
495 when C_Greater_Greater =>
497 Token = Tok_Greater_Greater;
507 when C_Left_Paren_Semicolon =>
509 Token = Tok_Left_Paren or else Token = Tok_Semicolon;
515 when C_Vertical_Bar_Arrow =>
517 Token = Tok_Vertical_Bar or else Token = Tok_Arrow;
520 Restore_Scan_State (Scan_State);
530 -- If we fall through it is not a reserved identifier
533 end Is_Reserved_Identifier;
535 ----------------------
536 -- Merge_Identifier --
537 ----------------------
539 procedure Merge_Identifier (Prev : Node_Id; Nxt : Token_Type) is
541 if Token /= Tok_Identifier then
546 S : Saved_Scan_State;
553 Restore_Scan_State (S);
560 -- Check exactly one space between identifiers
562 if Source (Token_Ptr - 1) /= ' '
563 or else Int (Token_Ptr) /=
564 Int (Prev_Token_Ptr) + Length_Of_Name (Chars (Prev)) + 1
571 Get_Name_String (Chars (Token_Node));
574 Buf : constant String (1 .. Name_Len) :=
575 Name_Buffer (1 .. Name_Len);
578 Get_Name_String (Chars (Prev));
579 Add_Char_To_Name_Buffer ('_');
580 Add_Str_To_Name_Buffer (Buf);
581 Set_Chars (Prev, Name_Find);
584 Error_Msg_Node_1 := Prev;
586 ("unexpected identifier, possibly & was meant here");
588 end Merge_Identifier;
594 procedure No_Constraint is
596 if Token in Token_Class_Consk then
597 Error_Msg_SC ("constraint not allowed here");
598 Discard_Junk_Node (P_Constraint_Opt);
602 ---------------------
603 -- Pop_Scope_Stack --
604 ---------------------
606 procedure Pop_Scope_Stack is
608 pragma Assert (Scope.Last > 0);
609 Scope.Decrement_Last;
612 Error_Msg_Uint_1 := UI_From_Int (Scope.Last);
613 Error_Msg_SC ("decrement scope stack ptr, new value = ^!");
617 ----------------------
618 -- Push_Scope_Stack --
619 ----------------------
621 procedure Push_Scope_Stack is
623 Scope.Increment_Last;
625 if Style_Check_Max_Nesting_Level
626 and then Scope.Last = Style_Max_Nesting_Level + 1
629 ("(style) maximum nesting level exceeded",
630 First_Non_Blank_Location);
633 Scope.Table (Scope.Last).Junk := False;
634 Scope.Table (Scope.Last).Node := Empty;
637 Error_Msg_Uint_1 := UI_From_Int (Scope.Last);
638 Error_Msg_SC ("increment scope stack ptr, new value = ^!");
640 end Push_Scope_Stack;
642 ----------------------
643 -- Separate_Present --
644 ----------------------
646 function Separate_Present return Boolean is
647 Scan_State : Saved_Scan_State;
650 if Token = Tok_Separate then
653 elsif Token /= Tok_Identifier then
657 Save_Scan_State (Scan_State);
658 Scan; -- past identifier
660 if Token = Tok_Semicolon then
661 Restore_Scan_State (Scan_State);
662 return Bad_Spelling_Of (Tok_Separate);
665 Restore_Scan_State (Scan_State);
669 end Separate_Present;
671 --------------------------
672 -- Signal_Bad_Attribute --
673 --------------------------
675 procedure Signal_Bad_Attribute is
677 Error_Msg_N ("unrecognized attribute&", Token_Node);
679 -- Check for possible misspelling
681 Get_Name_String (Token_Name);
684 AN : constant String := Name_Buffer (1 .. Name_Len);
687 Error_Msg_Name_1 := First_Attribute_Name;
688 while Error_Msg_Name_1 <= Last_Attribute_Name loop
689 Get_Name_String (Error_Msg_Name_1);
691 if Is_Bad_Spelling_Of
692 (AN, Name_Buffer (1 .. Name_Len))
695 ("\possible misspelling of %", Token_Node);
699 Error_Msg_Name_1 := Error_Msg_Name_1 + 1;
702 end Signal_Bad_Attribute;
704 -----------------------------
705 -- Token_Is_At_End_Of_Line --
706 -----------------------------
708 function Token_Is_At_End_Of_Line return Boolean is
712 -- Skip past blanks and horizontal tabs
715 while Source (S) = ' ' or else Source (S) = ASCII.HT loop
719 -- We are at end of line if at a control character (CR/LF/VT/FF/EOF)
720 -- or if we are at the start of an end of line comment sequence.
722 return Source (S) < ' '
723 or else (Source (S) = '-' and then Source (S + 1) = '-');
724 end Token_Is_At_End_Of_Line;
726 -------------------------------
727 -- Token_Is_At_Start_Of_Line --
728 -------------------------------
730 function Token_Is_At_Start_Of_Line return Boolean is
732 return (Token_Ptr = First_Non_Blank_Location or else Token = Tok_EOF);
733 end Token_Is_At_Start_Of_Line;